Mezzanine floors are often used in industrial environments, such as in warehouses, to provide uniformity in surface wear and structural integrity for relatively large areas which must undergo heavy traffic, particularly wheel-borne heavy loads. A typical mezzanine floor includes an underlying support layer of corrugated sheet metal, preferably 18 to 20 guage, and the corrugated metal is rigidly connected, or secured, to a building frame. The manner of securement depends upon whether the floor is located at ground level or at another level, such as a second or third floor, as in a modular storage deck used in a warehouse. The corrugated metal may be secured to vertical and/or horizontal structural support beams of various shapes and sizes. A single building may have a number of mezzanine floors.
An upper layer of panels is secured to the layer of corrugated metal by holding screws, and the top surfaces of the panels form the top surface of the mezzanine floor. These holding screws extend downwardly from the top surfaces of the panels, through the panels and into the relatively flat upper portions of the corrugated metal, for securement thereto. The panels are usually supported laterally by tongue and groove interconnections, which help interlock the panels to promote continuity of the floor and transfer wheel loads from panel to panel. Preferably, the tongue and groove between adjacent rows of panels reside above the flat upper portions of the corrugated metal.
In mezzanine floors of this type, the panels must be sufficiently sturdy to hold up against the heavy wheel loads common to industrial use, without delamination or without allowing any sudden punch through above the voids, or troughs, of the corrugated metal.
Another important characteristic of mezzanine flooring panels is uniformity in thickness and in surface conditions, within relatively tight tolerance ranges. In addition to being an indication of poor workmanship or design, such variations can create a hazardous condition for wheeled hand trucks, or any other wheel-supported material handling device, as well as a tripping hazard for pedestrian traffic.
Similar to any construction of a building or support structure, it is desirable to manufacture and install the panels of a mezzanine floor as inexpensively as possible.
Due largely to these factors, most mezzanine floors have utilized panels of wood-based construction, using one or more of the following wood based components: wood chips, wood strands, wood plies, etc. Wood has good structural strength characteristics, and it is also very workable in a manufacturing context.
While wood-based boards have proved acceptable, each type of wood-based panel is susceptible to one or more disadvantages. For instance, plywood is susceptible to delamination. The exposed upper surface of oriented strand board eventually flakes which creates a coarse, pitted surface, and the board is susceptible to wheel punch under heavy wheel loads. Other types of composite board are also susceptible to delamination and core failure.
For composite panels, the internal cohesive strength of the panel components must also be very high. Otherwise, the panels will be subject to wheel punch through or breaking apart under wheel loads. However, if the internal cohesiveness of the panels is too high, it is extremely difficult to install and accurately seat the holding screws, unless the panels are first counterbored. This extra counterboring step increases the labor steps necessary for installing the mezzanine floor, and the installation job is already labor intensive enough without the need to perform additional steps.
In addition to structural integrity, mezzanine panels must have a wear surface which is water resistant, durable, cleanable and which has non-skid characteristics. To achieve one or more of these features, it is known in the industry to treat, or finish, the surfaces of the panels prior to installation. However, such treatments can become rather expensive, and in many cases, a treatment which is beneficial for one particular feature can have adverse results with respect to a different feature.
For instance, a surface finishing treatment designed to improve non-skid characteristics may produce bumps or dimples on the floor which do in fact provide the desired non-skid feature. However, such bumps or dimples may make the floor extremely hard to clean effectively on a regular basis.
It is an object of this invention to overcome the limitations of prior mezzanine panels used in prior mezzanine floors. More particularly, it is an object of this invention to improve upon the structural integrity, the durability, the cleanability, the water resistance and the non-skid characteristics of a mezzanine floor, without significantly increasing manufacturing or finishing costs for the panels, without increasing installation steps or difficulties, and without raising environmental concerns.
It is another object of the invention to reduce the costs associated with, and to simplify, the installation of a mezzanine floor.